title: Efficient dehalogenation of automobile shredder residue in NaOH/ethylene glycol using a ball mill.
abstract: We investigated the effectiveness of sodium hydroxide/ethylene glycol (NaOH/EG) for dehalogenation of automobile shredder residue (ASR) using a ball mill. Efficient dehalogenation was achieved at atmospheric pressure by combining the use of EG (196 degrees C b.p.) as a replacement solvent for NaOH with ball milling, which improved contact between ASR and OH(-) in solution. Moderate NaOH concentrations and increased ball mill rotation speeds produced high dechlorination that was not significantly affected by the weight ratio of ASR to EG. NaOH/EG dechlorination increased with temperature with an apparent activation energy of 50 kJ mol(-1) confirming that the reaction proceeded under chemical reaction control. The modified shrinking-core model was appropriate to explain the dechlorination process. Low chloro levels in our NaOH/EG-treated ASR suggested that this material could be used for feedstock recycling and the wet process may be applicable for dehalogenation of other important waste streams.
authors.affiliation: Graduate School of Environmental Studies, Tohoku University, 6-6-07 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan.
authors.forename: Tomohito
authors.initials: T
authors.lastname: Kameda
authors.forename: Yuuzou
authors.initials: Y
authors.lastname: Fukuda
authors.forename: Kye-Sung
authors.initials: KS
authors.lastname: Park
authors.forename: Guido
authors.initials: G
authors.lastname: Grause
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Yoshioka
mesh_terms: D001336:Automobiles; D019855:Ethylene Glycol / Q000737:chemistry*; D054879:Halogenation; D007220:Industrial Waste; D012972:Sodium Hydroxide / Q000737:chemistry*; D018505:Waste Management / Q000379:methods*
chemical_list: D007220:Industrial Waste; D012972:Sodium Hydroxide; D019855:Ethylene Glycol